Making an auto typer from list view - vb.net

Question

I currently have everything working as it should except for one thing, right now I have the user type into a textbox, press the Add button and it inserts the text into the list view, when the autotyper starts it starts a timer tick with 6000 intervals and types the list but does not go back to the beginning of the list it repeats the last known phrase.
EX:
How can I make it start back over from the beginning if there is nothing left to be typed?
My code for the timer tick
intervalTimer_Tick.Start()
Dim SeprateLine As String
Dim Separator As Integer
If ListedItems.Contains(vbLf) Then
Separator = ListedItems.IndexOf(vbLf)
SeprateLine = ListedItems.Remove(Separator)
ListedItems = ListedItems.Substring(Separator + 1)
Else
SeprateLine = ListedItems
End If
SendKeys.Send(SeprateLine)
SendKeys.Send("{ENTER}")
If ListedItems <> "" Then
End If
End Sub
My code for button
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
For Each LVI As ListViewItem In ListView1.Items
If ListedItems = "" Then
ListedItems = LVI.Text
Else
ListedItems &= vbLf & LVI.Text
End If
Next
intervalTimer_Tick.Start()
End Sub

Answer 1

I think it's great you've started coding in VB.NET. You are almost there, but I want to give you a suggestion. Don't store your values on your user interface - store them in code off the UI thread. Using plain old objects to keep data makes it easier to write and read. Consider a List(Of string) to hold the items, and using a ListBox and DataSource to present the data. This allows for definite separation between what is UI and what is data.
Private ReadOnly items As New List(Of String)()
Private ReadOnly timer As New System.Threading.Timer(AddressOf autoType, Nothing, -1, -1)
Private Sub AddButton_Click(sender As Object, e As EventArgs) Handles AddButton.Click
Dim s = InputBox("Add item", "Add", Nothing)
If s IsNot Nothing Then items.Add(s)
ListBox1.DataSource = Nothing
ListBox1.DataSource = items
End Sub
Private Sub RemoveButton_Click(sender As Object, e As EventArgs) Handles RemoveButton.Click
Dim si = ListBox1.SelectedIndex
If si >= 0 Then
items.RemoveAt(si)
ListBox1.DataSource = Nothing
ListBox1.DataSource = items
End If
End Sub
Private Sub StartButton_Click(sender As Object, e As EventArgs) Handles StartButton.Click
' different buttons / handlers for different intervals
timer.Change(5000, 6000) ' 5s delay before first tick, 6s between subsequent ticks
End Sub
Private Sub autoType(state As Object)
' this ticks off the UI thread, so must Control.Invoke to run on the UI
Me.Invoke(Sub() SendKeys.Send(String.Join(vbLf, items)))
End Sub
To stop it, just change the timer again
timer.Change(-1, -1)